Progress on four flavor QCD with the HISQ action (2009)
Bazavov, MILC Collaboration: A., Bernard, C., DeTar, C., Freeman, W., Gottlieb, Steven, Heller, U. M., ...
We describe recent progress on generation of gauge configurations using the Highly Improved Staggered Quark (HISQ) action that was designed by the HPQCD/UKQCD collaboration. The HISQ action requires...
SU(2) chiral fits to light pseudoscalar masses and decay constants (2009)
Bazavov, A., Bernard, C., DeTar, C., Du, X., Freeman, W., Gottlieb, Steven, ...
We present the results of fits to recent asqtad data in the light pseudoscalar sector using SU(2) partially-quenched staggered chiral perturbation theory. Superfine (a~0.06 fm) and ultrafine (a~0.045...
Results from the MILC collaboration's SU(3) chiral perturbation theory analysis (2009)
Bazavov, A., Bernard, C., DeTar, C., Du, X., Freeman, W., Gottlieb, Steven, ...
We present the status of the MILC collaboration's analysis of the light pseudoscalar meson sector with SU(3) chiral fits. The analysis includes data from new ensembles with smaller lattice spacing,...
MILC results for light pseudoscalars (2009)
Bazavov, A., Bernard, C., DeTar, C., Du, X., Freeman, W., Gottlieb, Steven, ...
We present the latest preliminary results of the MILC collaboration's analysis of the light pseudoscalar meson sector. The analysis includes data from new ensembles with smaller lattice spacings,...
QCD equation of state at non-zero chemical potential (2009)
Bazavov, A., Bernard, C., DeTar, C., Freeman, W., Gottlieb, Steven, ...
We present our new results for the QCD equation of state at nonzero chemical potential at N_t=6 and compare them with N_t=4. We use the Taylor expansion method with terms up to sixth order in...
Visualization of semileptonic form factors from lattice QCD (2009)
Bernard, C., DeTar, C., Di Pierro, M., El-Khadra, A. X., Evans, R. T., Freeland, E. D., ...
Comparisons of lattice-QCD calculations of semileptonic form factors with experimental measurements often display two sets of points, one each for lattice QCD and experiment. Here we propose to...
B and D Meson Decay Constants (2009)
Bernard, C., DeTar, C., Di Pierro, M., El-Khadra, A. X., Evans, R. T., Freeland, E. D., ...
We present an update of our calculations of the decay constants of the D, D_s, B, and B_s mesons in unquenched 2+1 flavor QCD. We use the MILC library of improved staggered gauge ensembles at lattice...
Full nonperturbative QCD simulations with 2+1 flavors of improved staggered quarks (2009)
Bazavov, A., Bernard, C., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., ...
Dramatic progress has been made over the last decade in the numerical study of quantum chromodynamics (QCD) through the use of improved formulations of QCD on the lattice (improved actions), the...
HISQ action in dynamical simulations (2009)
Bazavov, A., Bernard, C., DeTar, C., Freeman, W., Gottlieb, Steven, Heller, U. M., ...
We report on recent progress in employing the Highly Improved Staggered Quark (HISQ) action introduced by the HPQCD/UKQCD collaboration in simulations with dynamical fermions. The HISQ action is an...
Electromagnetic splittings of hadrons from improved staggered quarks in full QCD (2008)
Basak, S., Bazavov, A., Bernard, C., DeTar, C., Freeman, W., Gottlieb, Steven, ...
We present our initial study of the electromagnetic splittings of charged and neutral mesons, and the violation of Dashen's theorem. Hadron masses are calculated on MILC N_f=2+1 QCD ensembles at...
Bailey, Jon A., Bernard, C., DeTar, C., Di Pierro, M., El-Khadra, A. X., Evans, R. T., ...
We calculate the form factor f_+(q^2) for B-meson semileptonic decay in unquenched lattice QCD with 2+1 flavors of light sea quarks. We use Asqtad-improved staggered light quarks and a Fermilab...
Bernard, C., DeTar, C., Di Pierro, M., El-Khadra, A. X., Evans, R. T., Freeland, E. D., ...
We present the first lattice QCD calculation of the form factor for B-> D* l nu with three flavors of sea quarks. We use an improved staggered action for the light valence and sea quarks (the MILC...
Baryon masses with improved staggered quarks (2007)
Bernard, C., Davies, C., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., ...
The MILC collaboration's simulations with improved staggered quarks are being extended with runs at a lattice spacing of 0.06 fm with quark masses down to one tenth the strange quark mass. We give a...
The 2+1 flavor topological susceptibility from the asqtad action at 0.06 fm (2007)
Bernard, C., Billeter, B., DeTar, C., Levkova, L., Gottlieb, Steven, Heller, U. M., ...
We report new data for the topological susceptibility computed on 2+1 flavor dynamical configurations with lattice spacing 0.06 fm, generated with the asqtad action. The topological susceptibility is...
The equation of state with nonzero chemical potential for 2+1 flavors (2007)
Bernard, C., Burch, T., DeTar, C., Levkova, L., Gottlieb, Steven, Heller, U. M., ...
We present results for the QCD equation of state with nonzero chemical potential using the Taylor expansion method with terms up to sixth order in the expansion. Our calculations are performed on...
QCD thermodynamics with 2+1 flavors at nonzero chemical potential (2007)
Bernard, C., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., Levkova, L., ...
We present results for the QCD equation of state, quark densities and susceptibilities at nonzero chemical potential, using 2+1 flavor asqtad ensembles with $N_t=4$. The ensembles lie on a trajectory...
Status of the MILC light pseudoscalar meson project (2007)
Bernard, C., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., Levkova, L., ...
We discuss the current status of our calculation of the physics of pi and K mesons using three dynamical flavors of improved staggered quarks. This year, we have a new ensemble with a lattice spacing...
Status of the MILC light pseudoscalar meson project (2007)
C. Bernard, C. Detar, L. Levkova, Steven Gottlieb, U. M. Heller, J. E. Hetrick, ...
We discuss the current status of our calculation of the physics of π and K mesons using three dynamical flavors of improved staggered quarks. This year, we have a new ensemble with a lattice spacing...
QCD equation of state with 2+1 flavors of improved staggered quarks (2006)
Bernard, C., Burch, T., DeTar, C., Gottlieb, Steven, Levkova, L., Heller, U. M., ...
We report results for the interaction measure, pressure and energy density for nonzero temperature QCD with 2+1 flavors of improved staggered quarks. In our simulations we use a Symanzik improved...
Low energy constants from the MILC Collaboration (2006)
Bernard, C., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., Osborn, L. Levkova J., ...
Based on ongoing simulations, we update our results for low energy constants, decay constants, and light quark masses. The simulations employ three dynamical flavors of improved staggered quarks.
The QCD equation of state with asqtad staggered fermions (2006)
Bernard, C., Burch, T., DeTar, C., Gottlieb, Steven, Levkova, L., Heller, U. M., ...
We report on our result for the equation of state (EOS) with a Symanzik improved gauge action and the asqtad improved staggered fermion action at $N_t=4$ and 6. In our dynamical simulations with 2+1...
Update on the physics of light pseudoscalar mesons (2006)
DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., Levkova, L., ...
We present an update of the MILC investigation of the properties of light pseudoscalar mesons using three flavors of improved staggered quarks. Results are presented for the $\pi$ and $K$ leptonic...
LOW ENERGY CONSTANTS FROM THE MILC COLLABORATION ∗ (2006)
C. Bernard, C. Detar, L. Levkova, Steven Gottlieb, U. M. Heller, J. E. Hetrick, ...
We present preliminary updates of results for QCD low energy constants.
Update on the physics of light pseudoscalar mesons (2006)
C. Bernard, C. Detar, Steven Gottlieb, L. Levkova, J. E. Hetrick, J. Osborn, ...
We present an update of the MILC investigation of the properties of light pseudoscalar mesons using three flavors of improved staggered quarks. Results are presented for the π and K leptonic decay...
More evidence of localization in the low-lying Dirac spectrum (2005)
Bernard, C., De Forcrand, Ph., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., Jahn, O., ...
We have extended our computation of the inverse participation ratio of low-lying (asqtad) Dirac eigenvectors in quenched SU(3). The scaling dimension of the confining manifold is clearer and very...
The locality of the fourth root of staggered fermion determinant in the interacting case (2005)
Bernard, C., DeTar, C., Gottlieb, Steven, Heller, U., Hetrick, J. E., Levkova, L., ...
The fourth root approximation in LQCD simulations with dynamical staggered fermions requires justification. We test its validity numerically in the interacting theory in a renormalization group...
Predictions from Lattice QCD (2005)
Kronfeld, Andreas S., Allison, I. F., Aubin, C., Bernard, C., Davies, C. T. H., DeTar, C., ...
In the past year, we calculated with lattice QCD three quantities that were unknown or poorly known. They are the $q^2$ dependence of the form factor in semileptonic $D\to Kl\nu$ decay, the decay...
Update on pi and K Physics (2005)
Bernard, MILC Collaboration: C., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., Levkova, L., ...
We present an update of the MILC studies of the physics of light pseudoscalars using improved staggered fermions. New runs at lighter quark mass, as well as increased statistics for older sets, are...
The Equation of State for QCD with 2+1 Flavors of Quarks (2005)
Bernard, C., Burch, T., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., ...
We report results for the interaction measure, pressure and energy density for nonzero temperature QCD with 2+1 flavors of improved staggered quarks. In our simulations we use a Symanzik improved...
Charmed meson decay constants in three-flavor lattice QCD (2005)
Aubin, C., Bernard, C., DeTar, C., Di Pierro, M., Freeland, E. D., Gottlieb, Steven, ...
We present the first lattice QCD calculation with realistic sea quark content of the D^+ meson decay constant f_{D^+}. We use the MILC Collaboration's publicly available ensembles of lattice gauge...
Update on pi and K Physics (2005)
C. Bernard, C. Detar, F. Maresca, J. Osborn, Steven Gottlieb, L. Levkova, ...
We present an update of the MILC studies of the physics of light pseudoscalars using improved staggered fermions. New runs at lighter quark mass, as well as increased statistics for older sets, are...
Leptonic decay constants f_Ds and f_D in three flavor lattice QCD (2004)
Simone, J. N., Aubin, C., Bernard, C., DeTar, C., Di Pierro, M., El-Khadra, A. X., ...
We determine the leptonic decay constants in three flavor unquenched lattice QCD. We use O(a^2)-improved staggered light quarks and O(a)-improved charm quarks in the Fermilab heavy quark formalism....
The scaling dimension of low lying Dirac eigenmodes and of the topological charge density (2004)
Aubin, MILC Collaboration: C., Bernard, C., Gottlieb, Steven, Gregory, E. B., Heller, Urs M., Hetrick, J. E., ...
As a quantitative measure of localization, the inverse participation ratio of low lying Dirac eigenmodes and topological charge density is calculated on quenched lattices over a wide range of lattice...
Topological susceptibility with three flavors of staggered quarks (2004)
Aubin, C., Bernard, C., Billeter, Brian, DeTar, C., Gottlieb, Steven, Gregory, E., ...
As one test of the validity of the staggered-fermion fourth-root determinant trick, we examine the suppression of the topological susceptibility of the QCD vacuum in the limit of small quark mass....
Results for light pseudoscalars from three-flavor simulations (2004)
Aubin, MILC Collaboration: C., Bernard, C., DeTar, C., Gottlieb, Steven, Gregory, E. B., Heller, Urs M., ...
We compute pseudoscalar meson masses and decay constants in partially quenched QCD with three dynamical flavors of improved staggered quarks. Fitting the lattice data to staggered chiral perturbation...
Aubin, MILC Collaboration: C., Bernard, C., DeTar, C., Gottlieb, Steven, Gregory, E. B., Heller, U. M., ...
As part of our program of lattice simulations of three flavor QCD with improved staggered quarks, we have calculated pseudoscalar meson masses and decay constants for a range of valence quark masses...
Light hadrons with improved staggered quarks: approaching the continuum limit (2004)
Aubin, C., Bernard, C., DeTar, C., Gottlieb, Steven, Gregory, E. B., Heller, U. M., ...
We have extended our program of QCD simulations with an improved Kogut-Susskind quark action to a smaller lattice spacing, approximately 0.09 fm. Also, the simulations with a approximately 0.12 fm...
High-precision lattice QCD confronts experiment (2004)
Davies, C.T.H., Follana, E., Gray, A., Lepage, G.P., Mason, Q., Nobes, M., ...
The recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test...
First determination of the strange and light quark masses from full lattice QCD (2004)
Aubin, C., Bernard, C., Davies, C.T.H., Detar, C., Gottlieb, S.A., Gray, A., ...
We compute the strange quark mass m and the average of the u and d quark masses (m) over cap using full lattice QCD with three dynamical quarks combined with the experimental values for the pi and K...
The Phase Diagram of High Temperature QCD with Three Flavors of Improved Staggered Quarks (2003)
Burch, T., DeTar, C. E., Gottlieb, Steven, Gregory, E. B., Heller, U. M., ...
We report on progress in our study of high temperature QCD with three flavors of improved staggered quarks. Simulations are being carried out with three degenerate quarks with masses less than or...
Pion and kaon physics with improved staggered quarks (2003)
Aubin, MILC Collaboration: C., Bernard, C., DeTar, C., Gottlieb, Steven, Gregory, E. B., Heller, Urs M., ...
We compute pseudoscalar meson masses and decay constants using staggered quarks on lattices with three flavors of sea quarks and lattice spacings $\approx 0.12$ fm and $\approx 0.09$ fm. We fit...
High-Precision Lattice QCD Confronts Experiment (2003)
Davies, C. T. H., Follana, E., Gray, A., Lepage, G. P., Mason, Q., Nobes, M., ...
We argue that high-precision lattice QCD is now possible, for the first time, because of a new improved staggered quark discretization. We compare a wide variety of nonperturbative calculations in...
The static quark potential in three flavor QCD (2000)
Bernard, C., Burch, T., Orginos, K., Toussaint, D., DeGrand, T. A., DeTar, C. E., ...
We study the effects of dynamical quarks on the static quark potential at distances shorter than those where string breaking is expected. Quenched calculations and calculations with three flavors of...
Light hadron spectrum with Kogut-Susskind quarks (1998)
Bernard, MILC Collaboration: C., DeTar, C., Gottlieb, Steven, Heller, Urs M., Hetrick, J. E., McNeile, C., ...
We made an extensive study of the light hadron spectrum using the Wilson gauge action and Kogut-Susskind quarks. Using both dynamical quarks and the quenched approximation, we determine hadron masses...
Local topological and chiral properties of QCD (1998)
De Forcrand, Ph., Perez, M. Garcia, Hetrick, J. E., Laermann, E., Lagae, J. F., Stamatescu, I. O.
To elucidate the role played by instantons in chiral symmetry breaking, we explore their properties in full QCD, around the critical temperature. We study in particular spatial correlations between...
Lattice Determination of Heavy-Light Decay Constants (1998)
Bernard, MILC Collaboration: C., DeGrand, T., DeTar, C., Gottlieb, Steven, Heller, Urs M., Hetrick, J. E., ...
We report on the MILC collaboration's calculation of $f_B$, $f_{B_s}$, $f_D$, $f_{D_s}$, and their ratios. Our central values come from the quenched approximation, but the quenching error is...
Topological Properties of the QCD Vacuum at $T$=0 and $T \sim T_{c}$ (1998)
De Forcrand, Philippe, Pérez-Garcia, M, Hetrick, J E, Stamatescu, I O
We study on the lattice the topology of SU(2) and SU(3) Yang-Mills theories at zero temperature and of QCD at temperatures around the phase transition. To smooth out dislocations and the UV noise we...
Critical Behavior at the Chiral Phase Transition (1997)
Bernard, C., Blum, T., DeTar, C. E., Heller, U. M., Gottlieb, S., Hetrick, J. E., ...
Quantum chromodynamics with two zero mass flavors is expected to exhibit a phase transition with O(4) critical behavior. Fixing the universality class is important for phenomenology and for...
De Forcrand, Ph., Perez, M. Garcia, Hetrick, J. E.
We study topological properties of SU(3) gauge theory using improved cooling. In the absence of fermions, we measure a topological susceptibility of $(182(8) MeV)^4$ and an instanton size $\sim 0.6$...
Hetrick, J. E., De Forcrand, Ph.
We present a new method of gauge fixing to standard lattice Landau gauge, Max Re Tr $\sum_{\mu,x}U_{\mu,x}$, in which the link configuration is recursively smeared; these smeared links are then gauge...
Three topics in the Schwinger model (1997)
De Forcrand, Ph., Hetrick, J. E., Takaishi, T., Van Der Sijs, A. J.
1. We compare Monte Carlo results with analytic predictions for the fermion condensate, in the massive one-flavour Schwinger model. 2. We illustrate on the Schwinger model how to facilitate...
The equation of state for QCD from the lattice (1997)
Bernard, C W, Blum, T, DeTar, C E, McNeile, C, Gottlieb, S, Rummukainen, K, ...
The equation of state for two flavor QCD at N_t=6 (1996)
Blum, T., Detar, C., Gottlieb, S., Heller, U. M., Hetrick, J. E., ...
We calculate the two flavor equation of state for QCD on lattices with lattice spacing a=(6T)^{-1} and find that cutoff effects are substantially reduced compared to an earlier study using...
Simulating QCD at finite density with static quarks (1996)
Blum, T., Hetrick, J. E., Toussaint, D.
We study lattice QCD in the limit that the quark mass and chemical potential are simultaneously made large, resulting in a controllable density of quarks which do not move; this is similar in spirit...
Aspects of Confinement and Chiral Dynamics in 2-d QED at Finite Temperature (1996)
Rodriguez, R., Hosotani, Y., Hetrick, J. E., Iso, S.
We evaluate the Polyakov loop and string tension at zero and finite temperature in $QED_2.$ Using bozonization the problem is reduced to solving the Schr\"odinger equation with a particular potential...
Assorted weak matrix elements involving the bottom quark (1996)
Bernard, C., Blum, T., DeGrand, T., DeTar, C. E., Gottlieb, Steven, Heller, U. M., ...
As part of a larger project to estimate the fB decay constant, we are recalculating fB_static using a variational smearing method in an effort to improve accuracy. Preliminary results for the static...
Thermodynamics for two flavor QCD (1996)
Bernard, C., Blum, T., DeTar, C. E., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., ...
We conclude our analysis of the N_t=6 equation of state for two flavor QCD, first described at last year's conference. We have obtained new runs at am_q=0.025 and improved runs at am_q=0.0125. The...
Confinement and Chiral Dynamics in the Multi-flavor Schwinger Model (1996)
Hosotani, Y., Rodriguez, R., Hetrick, J. E., Iso, S.
Two-dimensional QED with $N$ flavor fermions is solved at zero and finite temperature with arbitrary fermion masses to explore QCD physics such as chiral condensate and string tension. The problem is...
The N$_{t}$ = 6 equation of state for two flavor QCD (1995)
Bernard, C W, Blum, T, DeTar, C E, Gottlieb, S, Heller, U M, Hetrick, J E, ...
The interplay between mass, volume, \theta, and in N-flavor QED_2 (1995)
Hetrick, J. E., Hosotani, Y., Iso, S.
The Schwinger model (QED_2) with N flavors of massive fermions on a circle of circumference L, or equivalently at finite temperature T, is reduced to a quantum mechanical system of N-1 degrees of...
The $N_t=6$ equation of state for two flavor QCD (1995)
Bernard, C., Blum, T., DeTar, C., Gottlieb, Steven, Heller, U. M., Hetrick, J. E., ...
We improve the calculation of the equation of state for two flavor QCD by simulating on $N_t=6$ lattices at appropriate values of the couplings for the deconfinement/chiral symmetry restoration...
F$_{B}$ quenched and unquenched (1995)
Bernard, C W, Blum, T, De, A, DeGrand, T A, DeTar, C E, Gottlieb, S, ...
Results for f_B, f_{B_s}, f_D, f_{D_s}, and their ratios are presented. High statistics quenched runs at \beta=5.7, 5.85, 6.0, and 6.3, plus a run still in progress at \beta=6.52 make possible a...
The Massive Multi-flavor Schwinger Model (1995)
Hetrick, J. E., Hosotani, Y., Iso, S.
QED with N species of massive fermions on a circle of circumference L is analyzed by bosonization. The problem is reduced to the quantum mechanics of the 2N fermionic and one gauge field zero modes...
The continuum limit of the lattice Gribov problem and a solution based on Hodge decomposition (1995)
High-precision lattice QCD confronts experiment
Davies, C.T.H., Follana, E., Gray, A., Lepage, G.P., Mason, Q., Nobes, M., ...
The recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test...
First determination of the strange and light quark masses from full lattice QCD
Aubin, C., Bernard, C., Davies, C.T.H., Detar, C., Gottlieb, S.A., Gray, A., ...
We compute the strange quark mass m and the average of the u and d quark masses (m) over cap using full lattice QCD with three dynamical quarks combined with the experimental values for the pi and K...
High-precision lattice QCD confronts experiment
Davies, C.T.H., Follana, E., Gray, A., Lepage, G.P., Mason, Q., Nobes, M., ...
The recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test...
First determination of the strange and light quark masses from full lattice QCD
Aubin, C., Bernard, C., Davies, C.T.H., Detar, C., Gottlieb, S.A., Gray, A., ...
We compute the strange quark mass m and the average of the u and d quark masses (m) over cap using full lattice QCD with three dynamical quarks combined with the experimental values for the pi and K...